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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Caracterização dos diferentes transcritos produzidos pelo locus HJURP (HollidayJunctionRecognizing-Protein) em células de glioblastoma /

Petitto Netto, Renato. January 2018 (has links)
Orientador: Valeria Valente / Banca: Josane de Freitas Sousa / Banca: Cleslei Fernando Zanelli / Resumo: O glioblastoma (GBM) é o tipo mais comum e mortal de tumor cerebral, sendo que os pacientes apresentam uma sobrevida média de apenas 14 meses. O tratamento é realizado com remoção cirúrgica da massa tumoral, seguida de radioterapia e quimioterapia, porém sua eficácia é muito reduzida devido a acelerada atividade proliferativa e elevada resistência das células tumorais aos agentes genotóxicos. Dados do nosso grupo sustentam a hipótese de que este quadro pode estar associado em parte ao ganho de competência na atividade de reparo de DNA. Demonstramos anteriormente que, a HJURP (HollidayJunctionRecognizing Protein), uma proteína envolvida em reparo de DNA e montagem da cromatina centromérica, está superexpressa nos astrocitomas e que seus altos níveis de expressão estão correlacionados com o pior prognóstico dos pacientes. Dados da literatura evidenciam a existência de três RNAs mensageiros para o locus HJURP. O maior deles, denominado hjurp1, apresenta 9 éxons e codifica a isoformaprotéica A, que contém 748 aminoácidos. Os transcritos 2 e 3 apresentam deleção de alguns éxons, codificando proteínas hipoteticamente menores. Embora existam vários cDNAs depositados no GenBank que corroboram a expressão destes três mRNAs, não há dados na literatura sobre seu padrão de expressão ou a funcionalidade destas isoformas. Sendo assim, neste projeto avaliamos a expressão dos diferentes transcritos do locus HJURP em células de GBM, amostras de diferentes graus de astrocitoma, pares de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Glioblastoma (GBM) is the most common and lethal brain tumor in humans, with a median survival rate of ~ 14 months. Standard optimized treatment implies in surgery, followed by radiation and chemotherapy, but it has low efficacy due to tumor fast proliferative activity and high resistance against genotoxic agents. Preliminary data from our group showed that HJURP (Holliday Junction Recognizing Protein), a protein which plays a central role in chromatin assembly and is related to take part in double-stranded DNA breaks (DSBs) repair, is overexpressed in astrocytomas. High levels of this protein have been associated with patient pour prognosis. According to the literature, three transcript variants are predicted to encode HJURP gene. The variant (2) and (3) differ from the main splice variant (1) by the exclusion of some exons, generated by exon skipping. Although many cDNA sequences have been deposited on GeneBank database, it is still unclear their functions and expression pattern among tumors. Thus, in this work, we aimed to evaluate the expression of the three variants of HJURP gene in GBM cells, patient samples of different grades of astrocytoma, and different tumor and non-tumor cell lines. Expression of all transcripts was confirmed by conventional PCR in non-tumoral astrocytes (ACBRI371) and GBM cell lines (U87MG, U138MG, and U251MG). However, T98G and U343MG showed a distinct pattern. The variant (1) was detected in both cell lines, but the variant (3) was only detectable in T98G cells. Using quantitative PCR (q-PCR) we demonstrated that all transcripts were expressed at higher levels in GBM cells than in non-tumoral astrocytes. As we expected, T98G showed the highest levels of HJURP expression (variants 1,2 and 3). We also observed that variant (1) is more abundant in the cell lines. Albeit, there was an overall increase... (Complete abstract click electronic access below) / Mestre
32

Avaliação do efeito sinérgico do butirato de sodio e tyrphostin AG1478 na proliferação de glioblastoma multiforme

Duque, Marienela Buendia January 2016 (has links)
Introdução: Gliomas são os tumores cerebrais mais frequentes em pacientes com neoplasias de Sistema Nervoso Central (SNC), sendo o Glioblastoma Multiforme (GBM) o mais agressivo e letal deles. Apesar dos esforços na melhoria dos tratamentos atuais, o prognóstico para os pacientes com GBM continua sendo incerto. Sendo necessário o uso de novas estratégias terapêuticas que visem melhorar o manejo dos gliomas malignos. A combinação de terapias que agem nas principais vias de sinalização celular envolvidas na progressão do câncer poderia potencializar o efeito antitumoral das monoterapias. Métodos: As linhagens celulares U-87 e A-172 foram tratadas com o anti-EGFR tyrphostin AG1478, o inibidor de histonas deacetilases butirato de sódio (NaB) ou a combinação de ambos, por 72 horas. Tanto a viabilidade avaliada em 72 horas quanto a proliferação celular a longo prazo foram medidas através do ensaio de exclusão com azul de tripan em câmara de Neubauer. A influência do tratamento no ciclo celular e a capacidade de formar colônias foram avaliadas através da marcação com iodeto de propídeo e ensaio clonogênico, respectivamente. Resultados: Foi possível observar que o tratamento combinado com AG1478 e NaB foi capaz de reduzir a viabilidade e a proliferação celular na linhagem U-87 de GBM. Conclusão: Nosso trabalho mostrou que a inibição da via do receptor do fator de crescimento epidérmico (EGFR) combinada com a inibição das histonas deacetilases foi mais efetiva que as monoterapias na inibição da viabilidade e a proliferação celular. Esta redução foi significativa na linhagem U-87. Futuros estudos devem ser feitos para descobrir as possíveis interações entre as duas vias de sinalização em GBM. / Introduction: Gliomas are the most frequent brain tumors, in patients with Central Nervous system (NCS) malignancies, being the Glioblastoma Multiforme the most aggressive and lethal of all. Despite current multimodality treatment efforts, the prognosis for GBM patients remains poor. New therapeutic strategies that target these pathways to improve the treatment of malignant gliomas are needed. Combination of therapies with synergistic effects in the cellular signaling pathways of cancer could potentiate the anti-tumor effect of monotherapy alone. Methods: U87 and A172 cell lines were treated with the anti-EGFR Thyrphostin AG1478, the Histone Deacetylase inhibitor (HDACi) Sodyum Butyrate (NaB), or combination of both, for 72 hours. The cellular proliferation in short and in a long time was measured through the trypan-blue assay on neubauer chamber, the influence on the cell cycle and the capability of form colonies was evaluated by nuclear staining with propidium iodide and clonogenic assay respectively. Results: We found that combined treatment with AG1478 and NaB, are able to reduce the viability and proliferation in U-87. Conclusion: Our work show that combined inhibition of both epidermal growth factor receptor and histone deacetylases was able to reduce cell proliferation in GBM cell lines. This reduction was considerably significant in U-87 cell lines when compared with individual treatments. Further studies should be performed to discover the possible crosstalk between the signaling pathways of both targets in GBM.
33

Avaliação do efeito sinérgico do butirato de sodio e tyrphostin AG1478 na proliferação de glioblastoma multiforme

Duque, Marienela Buendia January 2016 (has links)
Introdução: Gliomas são os tumores cerebrais mais frequentes em pacientes com neoplasias de Sistema Nervoso Central (SNC), sendo o Glioblastoma Multiforme (GBM) o mais agressivo e letal deles. Apesar dos esforços na melhoria dos tratamentos atuais, o prognóstico para os pacientes com GBM continua sendo incerto. Sendo necessário o uso de novas estratégias terapêuticas que visem melhorar o manejo dos gliomas malignos. A combinação de terapias que agem nas principais vias de sinalização celular envolvidas na progressão do câncer poderia potencializar o efeito antitumoral das monoterapias. Métodos: As linhagens celulares U-87 e A-172 foram tratadas com o anti-EGFR tyrphostin AG1478, o inibidor de histonas deacetilases butirato de sódio (NaB) ou a combinação de ambos, por 72 horas. Tanto a viabilidade avaliada em 72 horas quanto a proliferação celular a longo prazo foram medidas através do ensaio de exclusão com azul de tripan em câmara de Neubauer. A influência do tratamento no ciclo celular e a capacidade de formar colônias foram avaliadas através da marcação com iodeto de propídeo e ensaio clonogênico, respectivamente. Resultados: Foi possível observar que o tratamento combinado com AG1478 e NaB foi capaz de reduzir a viabilidade e a proliferação celular na linhagem U-87 de GBM. Conclusão: Nosso trabalho mostrou que a inibição da via do receptor do fator de crescimento epidérmico (EGFR) combinada com a inibição das histonas deacetilases foi mais efetiva que as monoterapias na inibição da viabilidade e a proliferação celular. Esta redução foi significativa na linhagem U-87. Futuros estudos devem ser feitos para descobrir as possíveis interações entre as duas vias de sinalização em GBM. / Introduction: Gliomas are the most frequent brain tumors, in patients with Central Nervous system (NCS) malignancies, being the Glioblastoma Multiforme the most aggressive and lethal of all. Despite current multimodality treatment efforts, the prognosis for GBM patients remains poor. New therapeutic strategies that target these pathways to improve the treatment of malignant gliomas are needed. Combination of therapies with synergistic effects in the cellular signaling pathways of cancer could potentiate the anti-tumor effect of monotherapy alone. Methods: U87 and A172 cell lines were treated with the anti-EGFR Thyrphostin AG1478, the Histone Deacetylase inhibitor (HDACi) Sodyum Butyrate (NaB), or combination of both, for 72 hours. The cellular proliferation in short and in a long time was measured through the trypan-blue assay on neubauer chamber, the influence on the cell cycle and the capability of form colonies was evaluated by nuclear staining with propidium iodide and clonogenic assay respectively. Results: We found that combined treatment with AG1478 and NaB, are able to reduce the viability and proliferation in U-87. Conclusion: Our work show that combined inhibition of both epidermal growth factor receptor and histone deacetylases was able to reduce cell proliferation in GBM cell lines. This reduction was considerably significant in U-87 cell lines when compared with individual treatments. Further studies should be performed to discover the possible crosstalk between the signaling pathways of both targets in GBM.
34

Epilepsia como manifestação de tumor cerebral na infância e adolescência: características e desfechos clínicos / Epilepsy as a sign of brain tumor in the childhood and adolescence: features and outcome

Marília Rosa Abtibol Bernardino 23 November 2015 (has links)
A epilepsia associada a tumor cerebral é uma condição debilitante, causadora de importante prejuízo sobre a qualidade de vida dos que sofrem desta condição. Relacionada à grande refratariedade ao tratamento medicamentoso, tanto a epilepsia quanto o uso de drogas antiepilépticas (DAEs) predispõem à deterioração das funções cognitivas. Em casos raros, a epilepsia secundária a tumor cerebral pode ser devastadora, aumentando os riscos de morte súbita. Buscando auxiliar a tomada de decisões e enfatizando os benefícios de uma discussão ampla entre equipes de oncologia, neurologia infantil, epilepsia e neurocirurgia, este trabalho objetiva descrever as características clínicas gerais, eletroencefalográficas, histopatológicas dos pacientes, verificar o impacto do tratamento cirúrgico sobre a epilepsia quanto ao desfecho clínico relacionado ao controle das crises, comparar os resultados da avaliação cognitiva nos períodos pré e pós-operatórios e descrever a ocorrência de complicações cirúrgicas intra-operatórias, pós-operatórias e óbitos. Trata-se de estudo observacional transversal retrospectivo, por revisão de prontuários de pacientes com idade inferior a 19 anos quando submetidos à cirurgia para tratamento de epilepsia refratária secundária a tumores cerebrais entre 1996 e 2013, pela equipe do Centro de Cirurgia de Epilepsia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto. Para análise dos desfechos quanto à incidência de crises, utilizou-se a classificação de Engel, adaptada para uso após o primeiro ano da cirurgia. Procedeu-se à análise descritiva dos dados. Foram incluídas 27 crianças, com média de 6,0 anos (3 meses a 15,8 anos) no início dos sintomas. O intervalo entre o início das crises epilépticas e o diagnóstico do tumor foi de 3,6 anos (um mês a 14,5 anos). A média da quantidade de drogas antiepilépticas (DAEs) utilizadas antes da cirurgia foi 3,6. A média da idade no diagnóstico do tumor cerebral foi 9,7 anos (10 meses a 16,8 anos). A localização do tumor foi lobo temporal em 59,2%, sendo ganglioglioma e DNET os mais frequentes, em igual proporção, 33,3%. Envolvimento de área eloquente ocorreu em 18,5%. A vídeomonitorização eletrográfica evidenciou descargas focais na área tumoral em 85,2%. O intervalo entre o diagnóstico tumoral e a realização da cirurgia foi de 1,5 anos (dias a 7 anos). A média de idade dos pacientes no momento da cirurgia foi 11,3 anos (3 a 17, 4 anos). A ressecção tumoral foi completa em 88,8% dos pacientes. Complicação pós-cirúrgica, osteomielite, ocorreu em 1 (3,7%). Um paciente (3,7%) com oligodendroglioma anaplásico foi a óbito após 2 anos da cirurgia. Os desfechos clínicos relacionados ao controle de crises dos pacientes submetidos à cirurgia foram satisfatórios, com Engel I correspondendo a 92,6% no primeiro ano pós-operatório. Apenas 14,8% apresentaram Engel III - IV durante todo o período de seguimento. A média do tempo para retirada das DAEs após a cirurgia foi de 3,2 anos (1,7 a 7 anos). Alterações neurológicas após a cirurgia ocorreram em 18,5%, sendo os déficits neurológicos focais transitórios. Evoluíram com melhora do perfil intelectual 31,3%, inalterado 50% e piora 18,7%. A cirurgia para tratamento da epilepsia secundária a tumor cerebral evidenciou-se uma modalidade terapêutica potencialmente curativa e segura, portanto, o diagnóstico tumoral não pode ser postergado / Tumor-associated epilepsy is a debilitating condition causing injury to the quality of life of those who suffer from a brain tumor. It has been shown to have a greater refractivity to antiepileptic drug therapy. Both epilepsy and the use of antiepileptic drugs have a predisposition to the deterioration of cognitive functions. In rare cases tumor-associated epilepsy can be devastating, increasing the risk of sudden death. Seeking help with decisionmaking and emphasizing the benefits of a broad discussion among oncology teams, child neurology, epilepsy and neurosurgery, this paper describes the general, clinical, electroencephalographic, and histopathological patient characteristics, verifies the impact of surgical treatment of epilepsy as the clinical outcome related to the control of seizures, compares the result of cognitive assessment in the pre to the postoperative and describes the occurrence of intraoperative surgical complications and postoperative deaths. It is a retrospective cross-sectional observational study, by review of medical records of patients under the age of 19 who underwent surgery to treat tumor-associated epilepsy between 1996 and 2013, by the Epilepsy Surgery Center of the Hospital of School of Medicine of Ribeirão Preto, São Paulo University. For analysis of outcomes in the incidence of crises, the Engel classification was used and adapted for use after the first year of surgery. It was used with the descriptive analysis of the data. Twenty seven children were included, with a mean of 6.0 years (3 months to 15.8 years) at the beginning of symptoms. The interval between the onset of seizures and the diagnosis of the tumor was 3.6 years (1 month to 14.5 years). The average number of antiepileptic drugs (AEDs) used before surgery was 3.6. The average age at diagnosis of brain tumor was 9.7 years (10 months to 16.8 years). The tumor site was the temporal lobe in 59.2% of patients and ganglioglioma and DNET were the most common, in equal proportion, 33.3%. Eloquent area of involvement occurred in 18.5%. The electrographic video monitoring showed focal discharges at the tumor site in 85.2% of patients. The interval between tumor diagnosis and the surgery was 1.5 years (days to 7 years). The average patient age at surgery was 11.3 years (3-17, 4 years). Tumor resection was complete in 88.8% of patients. Post-surgical complication, osteomyelitis, occurred in 1 (3.7%) of patients. Only one patient (3,7%) had anaplastic oligodendroglioma and dead two years after surgery. Clinical outcomes related to the control of seizures in patients undergoing surgery were satisfactory, with Engel I corresponding to 92,6% in the first year of follow up. Only 14.8% had Engel III - IV during the follow-up period. The average time for withdrawal of AEDs after surgery was 3.2 years (1.7 to 7 years). Neurological changes after surgery occurred in 18.5%, and were transient focal neurological deficits. The improvement of the intellectual profile occurred in 31.3%, unchanged in 50% and 18.7% worsened. Surgery to treat tumor-associated epilepsy showed up a potentially curative and safe therapeutic modality, therefore, tumor diagnosis cannot be postponed
35

Utilização dos mapas de coeficiente aparente de difusão para o diagnóstico de tumores cerebrais in vivo / Use of apparent diffusion coefficient maps for in vivo diagnostic of brain tumors

Souza, Edna Marina de, 1982- 19 August 2018 (has links)
Orientadores: Eduardo Tavares Costa, Gabriela Castellano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-19T05:34:48Z (GMT). No. of bitstreams: 1 Souza_EdnaMarinade_M.pdf: 4414073 bytes, checksum: bbe8987220fdc40a9373938439cb0a49 (MD5) Previous issue date: 2011 / Resumo: Em geral, processos patológicos tais como as transformações neoplásicas das células tendem a alterar a magnitude da organização estrutural do tecido pela reorganização ou destruição de elementos membranosos ou por alterações de celularidade. Tais alterações reetem na mobilidade dos prótons que pode ser avaliada por imagens poderadas por difusão (DW), a partir das quais são obtidos os mapas de Coeficiente Aparente de Difusão (ADC), que expressam a magnitude da difusão das moléculas de água em pontos de uma determinada região de interesse (ROI). O presente estudo teve por objetivo principal explorar a utilização destes mapas na diferenciação, em 2D e 3D, entre tecidos cerebrais sadios de indivíduos controle e tecidos tumorais de pacientes acometidos por glioblastoma multiforme ou meningeoma, dois tipos de tumores cerebrais de grande incidência e que podem, dependendo da localização, serem confundidos entre si em imagens de ressonância magnética (RM) estruturais. Secundariamente, foi avaliada a inuência da posição das ROIs 3D usadas para calcular os valores de ADC de controles, e também a inuência (nos valores de ADC destes indivíduos) de incluir ou excluir os ventrículos laterais destas ROIs. Os mapas de ADC foram calculados a partir de imagens de RM ponderadas por T2 e difusão, utilizando uma rotina computacional desenvolvida em estudos anteriores. A partir destes mapas, verificou-se que em 2D as médias dos valores de ADC encontrados para glioblastomas, meningeomas e tecidos sadios do grupo controle foram, respectivamente, 2,6x 10-4 mm2/s, 4,88x 10-4 mm2/s e 8,99x 10-4 mm2/s, com valor de p < 0; 05, indicando a existência de diferenças estatisticamente significantes entre os grupos, confirmadas através de um teste ANOVA e da análise de Bonferroni. Nas análises 3D, as médias de valores de ADC obtidas para os mesmos três grupos foram respectivamente 2,83 x 10-4 mm2/s, 5,37 x 10-4 mm2/s e 9,27 x 10-4 mm2/s. Um teste ANOVA realizado entre os grupos controle e os dois grupos de pacientes demonstrou haver diferenças significantes entre eles (p < 0; 05). A análise de Bonferroni confirma a distinção entre tecidos cerebrais sadios de indivíduos controle e glioblastomas, mas aponta para a indistinção entre tecidos cerebrais sadios e meningeomas. A análise dos valores de ADC 3D do grupo controle com e sem presença de porções dos ventrículos laterais nas ROIs mostrou que pequenas porções de ventrículos não interferem significativamente na possibilidade de distinção entre tecidos cerebrais sadios e os tumores estudados / Abstract: In general, pathologic processes, such as neoplasic cell changes, tend to alter the magnitude of structural organization by destruction or reorganization of membranous elements or by a change in cellularity. These changes will also have an impact on proton mobility, which can be followed up by Diffusion-Weighted Imaging (DWI). From DWI is obtained the ADC (Apparent Diffusion Coefficient) map, which is a representation of the magnitude of water diffusion at points of a given region of interest (ROI). The present study explored the use of 2D and 3D ADC maps for the distinction between healthy brain tissue of controls and tumor tissue of patients with glioblastoma multiforme or meningioma. These high-incidence brain tumors can be confused in structural MR images. Secondarily, we evaluate the inuence of ROI location in the brain regarding ADC control values, and the inuence of position of 3D ROIs used for calculate ADC values of controls and evaluate the effect of inclusion or exclusion of lateral ventricles in these ROIs. ADC maps were calculated from MRI T2 and DWI using a computational tool developed in previous studies. From the 2D ADC maps, the mean ADC values found for glioblastomas, meningiomas and healthy brain tissue were 2.6 x 10-4 mm2/s, 4.88 x 10-4 mm2/s and 8.99 x 10-4 mm2/s, respectively. The analysis of variance (ANOVA) resulted in p-value < 0; 05, indicating the existence of significant differences between these groups, confirmed by using of the Bonferroni analysis. In the 3D analysis, the mean ADC values obtained for the same three groups were respectively 2.83 x 10-4 mm2/s, 5.37 x 10-4 mm2/s and 9.27 x 10-4 mm2/s. The ANOVA resulted in p-value < 0:05. In this case, the Bonferroni analysis confirms the distinction between healthy brain tissue and glioblastoma, but points to the difficulty of distinction between healthy brain tissue and meningioma. The analysis of 3D ADC values in the control group with and without the presence of portions of the lateral ventricles in the ROIs showed that small amounts of the ventricles does not significantly interfere with the ability to distinguish between healthy brain tissue and tumors studied / Mestrado / Engenharia Biomedica / Mestre em Engenharia Elétrica
36

Tissue database of autofluorescence response to improve intra-operative diagnosis of primitive brain tumors / Base de données sur le signal d'autofluorescence des tissus pour améliorer le diagnostic per-opératoire des tumeurs cérébrales

Poulon, Fanny 26 September 2018 (has links)
Le premier traitement standard pour les tumeurs cérébrales est la résection chirurgicale. Dans cette procédure un enjeu important demeure, l'identification des berges tumorales pour assurer une résection totale et éviter le risque de récidive pour le patient. A ce jour aucune technique d'imagerie peropératoire est capable de résoudre l'infiltration tumorale du tissu sain. La norme pour le diagnostic des berges tumorales est l'analyse histologique des biopsies. Une méthode ex vivo qui requiert un à plusieurs jours pour fournir ler apport pathologique final, un lapse de temps qui peut s'avérer fatal pour le patient. La microscopie optique a récemment été développer vers une utilisation clinique peropératoire pour répondre à cet enjeu. Dans travail, la technique de microscopie à deux-photons a été préférée pouressayer de répondre à cette problématique. Cette méthode donne accès à deux contrastes d'imagerie, la génération de seconde harmonique et l’émission de fluorescence, qui peuvent être combinés à des mesures quantitatives, tel que la spectroscopie et le temps de vie de fluorescence. Combiner ces quatre modalités de détection donnera une information complète sur la structure et le métabolisme de la région observée. Pour soutenir le développement technique vers une sonde endomicroscopique visant une utilisation peropératoire, les données en résultants doivent être fiables, et se montrer d'un intérêt pour le chirurgien. Par conséquent, une base de données sur le signal d'autofluorescence des tissus a été construite et présentée dans ce manuscrit, avec des algorithmes capables de discriminer de façon fiable les régions tumorales des régions saines. Des algorithmes qui ont montré le potentiel d'être automatisé dans une configuration clinique, afin de fournir une réponse en temps-réel au chirurgien. / The first standard approach for brain tumor treatment is the surgical resection. In this protocol an important challenge remains, the identification of tumor margins to ensure a complete resection and avoid risk of tumor recurrence. Nowadays no intra-operative means of contrast are able to resolve infiltrated regions from healthy tissue. The standard for tumor margin diagnosis is the histological analysis of biopsies. An ex vivo method that requires one to several days to issue a final pathological reports, a time lapse that could be fatal to the patient. Optical microscopy have recently been developed towards an intra-operative clinical use to answer this challenge. In this work, the technique of two-photon microscopy based on the autofluorescence of tissue have been favored. This technique gives access to two imaging contrasts, the second-harmonic generation and emission of fluorescence, and can be combined to quantitative measurements, such as spectroscopy and fluorescence lifetime. The combination of these four modalities of detection will give a complete structural and metabolic information on the observed region. To support the technical development towards an endomicroscopic probe, the resulted data have to be reliable and proved to be of interest for the surgeon. Consequently, an extensive database of the autofluorescence response of brain tumor tissue have been constructed and presented in this manuscript, with algorithms able to discriminate with reliability tumoral from healthy regions. Algorithms that have shown potential to be automatized in a clinical setting, in order to give a real-time answer to the surgeons.
37

Pathogenic peptides to enhance treatment of glioblastoma: evaluation of RVG-29 from rabies virus and chlorotoxin from scorpion venom

January 2019 (has links)
abstract: Glioblastoma (GBM) is a highly invasive and deadly late stage tumor that develops from abnormal astrocytes in the brain. With few improvements in treatment over many decades, median patient survival is only 15 months and the 5-year survival rate hovers at 6%. Numerous challenges are encountered in the development of treatments for GBM. The blood-brain barrier (BBB) serves as a primary obstacle due to its innate ability to prevent unwanted molecules, such as most chemotherapeutics, from entering the brain tissue and reaching malignant cells. The GBM cells themselves serve as a second obstacle, having a high level of genetic and phenotypic heterogeneity. This characteristic improves the probability of a population of cells to have resistance to treatment, which ensures the survival of the tumor. Here, the development and testing of two different modes of therapy for treating GBM is described. These therapeutics were enhanced by pathogenic peptides known to improve entry into brain tissue or to bind GBM cells to overcome the BBB and/or tumor cell heterogeneity. The first therapeutic utilizes a small peptide, RVG-29, derived from the rabies virus glycoprotein to improve brain-specific delivery of nanoparticles encapsulated with a small molecule payload. RVG-29-targeted nanoparticles were observed to reach the brain of healthy mice in higher concentrations 2 hours following intravenous injection compared to control particles. However, targeted camptothecin-loaded nanoparticles were not capable of producing significant treatment benefits compared to non-targeted particles in an orthotopic mouse model of GBM. Peptide degradation following injection was shown to be a likely cause for reduced treatment benefit. The second therapeutic utilizes chlorotoxin, a non-toxic 36-amino acid peptide found in the venom of the deathstalker scorpion, expressed as a fusion to antibody fragments to enhance T cell recognition and killing of GBM. This candidate biologic, known as anti-CD3/chlorotoxin (ACDClx) is expressed as an insoluble protein in Nicotiana benthamiana and Escherichia coli and must be purified in denaturing and reducing conditions prior to being refolded. ACDClx was shown to selectively activate T cells only in the presence of GBM cells, providing evidence that further preclinical development of ACDClx as a GBM immunotherapy is warranted. / Dissertation/Thesis / Doctoral Dissertation Biological Design 2019
38

An Analysis of a Model of Risk and Resilience Among Parents of Pediatric Brain Tumor Survivors

Ach, Emily Lauren 15 August 2013 (has links)
No description available.
39

THE MENINGIOMA ENHANCER LANDSCAPE DELINEATES PROGNOSTIC SUBGROUPS AND DRIVES DRUGGABLE DEPENDENCIES

Prager, Briana C. 07 September 2020 (has links)
No description available.
40

Integrated Single Cell Imaging and RNA-Sequencing in Glioblastoma

Liu, Zhouzerui January 2023 (has links)
Glioblastoma (GBM) is the most common and aggressive primary brain tumor and is comprised of transcriptionally heterogeneous cells and a complex microenvironment. Despite decades of research effort, few treatments significantly benefit clinical outcomes. This may be, in part, due to the lack of tools to directly measure functional responses of these heterogeneous cell types under therapy. This thesis aims to advance the understanding of cell type-specific therapeutic response by the development and application of integrated single cell imaging and RNA sequencing technology. Chapter 1 provides an overview of GBM and its heterogeneity, how investigation of cell type-specific phenotypes would benefit the development of GBM treatments, and current sequencing and imaging technologies to examine cell phenotypes with single-cell resolution. Chapter 2 presents a new microfluidic technology for joint single cell imaging and RNA sequencing that can link imaging-based phenotypes and transcriptional identity of the same individual cells with high throughput, molecular capture efficiency, linking accuracy, and user-friendliness. Chapters 3 and 4 present applications of this technology in investigating cell type-specificities of GBM treatments. Chapter 3 focuses on the specificities of 5-aminolevulinic acid (5-ALA), an FDA approved fluorogenic agent, used in fluorescence guided surgery and reveals 5-ALA labeling is not specific to transformed glioma cells, which encourages further studies to systematically compare its performance with potential alternatives. Chapter 4 focuses on the specificities of drug responses by presenting a functional drug screening approach that directly links cell states measured by apoptosis indicators with transcriptional states, which greatly enhances the interpretability of single cell-resolved drug perturbation assays.

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